code: def test_line_opts_with_zlevel_z(fake_writer):
      c = (
          Line()
          .add_xaxis(["A", "B", "C"])
          .add_yaxis("series0", [1, 2, 4])
          .add_yaxis("series1", [2, 3, 6], z_level=2, z=1)
      )
      c.render()
      _, content = fake_writer.call_args[0]
      assert_in("zlevel", content)
      assert_in("z", content)
  
file_path: pyecharts/test/test_line.py
imports: from unittest.mock import patch
  from nose.tools import assert_equal, assert_in
  from pyecharts import options
  from pyecharts.charts import Line
label_desc: Use image node_id 5 for calling a global function with example usage: test_line_opts_with_zlevel_z(fake_writer) without return types